Variations in free secretory component levels in mucosal secretions of the rat

The present studies were conducted to compare the levels of free secretory component (SC) in a number of rat mucosal secretions and to determine whether SC content varies significantly during the four stages of the estrous cycle. Levels of SC, as measured by radioimmunoassay, were markedly different in various external secretions. Bile contained the highest amount, irrespective of whether SC was normalized to volume or protein. Concentrations of SC in saliva or uterine fluid from intact rats were approximately 20- to 30-fold less than measured in bile. When SC levels were normalized to protein, the SC to protein ratios in uterine, vaginal, and respiratory secretions were six to 18 times greater than values calculated in salivary and small intestinal fluids. Analysis of SC levels in mucosal secretions during the estrous cycle indicated significant variations occur in uterine and vaginal samples, but not in saliva or small intestinal secretions. In the uterine lumen, SC levels were highest at proestrus, partially elevated at estrus, and lowest at both days of diestrus. In contrast, vaginal SC levels were maximal at estrus and reduced at all other stages of the cycle. Immunoglobulin A content was also measured in uterine and vaginal secretions during the estrous cycle. Significant changes in IgA levels were found and these coincided with the changing pattern of SC. These results suggest hormones may modulate SC levels in reproductive tissues. In addition, our findings indicate variations in SC during the estrous cycle may direct the movement of IgA from tissue to lumen.     

Immunoglobulin and antibody content in the blood serum, coprofiltrate and saliva of patients with Sonne dysentery]

The authors studied the immunoglobulin and specific antibodies content of various classes in the serum, coprofiltrates and the saliva of 68 patients suffering from Sonne dysentery and in 48 healthy adult persons. Mancini's test demonstrated a significant elevation of IgG and IgM content in the blood of dysentery patients in comparison with that in healthy persons, and the absence of any changes in the IgA content. The titres of specific IgG-, IgA- and IgM-antibodies in determination in the modified Coombs' test increased consideerably during dysentery infection and were found in high titres during the first week of the disease; they reached the maximum during the second week and persisted at this level for 3 weeks. The greatest antibody elevation was in the IgA-class. Antibodies revealed in the coprofiltrates and the saliva of dysentery patients belonged to IgA- and IgG-class. There proved to be a correlation of the antibody changes in these two secretions.     

Detection of HIV-Gag p24-Specific Antibodies in Sera and Saliva of HIV-1-Infected Adults and in Sera of Infants Born to HIV-1-Infected Mothers

Secretory immunoglobulin A (IgA) is known to play an important role in the mucosal defense against a variety of pathogens. Although the role of IgA antibodies during sexual transmission of HIV is not clear, HIV-specific IgA antibodies have been detected in various mucosal secretions of HIV-infected individuals. Using a monoclonal antibody against human IgA, we established an ELISA system to detect anti-HIV p24 IgA antibodies in sera and saliva. We have analyzed the levels of anti-HIV p24 IgG and IgA antibodies in sera and saliva of 107 and 119 adults, respectively, with HIV infection at different clinical stages, and in the sera of 13 infants born to HIV-infected mothers. The level of anti-HIV p24 IgA antibodies was lower in sera and higher in saliva as compared to that of anti-HIV p24 IgG antibodies. Where the percentage of HIV-specific serum antibody-positive cases decreased with disease progression, that of saliva antibody-positive cases increased in AIDS patients. Among the 13 infants born to HIV-infected mothers, 7 infants were HIV-p24-specific serum IgA positive. These sera were negative for anti-HIV p24 secretory IgA, suggesting that some infants develop their own immune responses against HIV infection. Thus, the detection of HIV-specific IgA antibodies, especially in saliva, could be a simple and reliable test for the diagnosis of HIV infection.     

Estradiol regulation of the secretory immune system in the female reproductive tract: IgA in uterine and vaginal secretions of rats following portacaval anastomosis

The uterine immune system is under the control of estradiol which acts to increase the levels of both IgA and secretory component (SC) in uterine secretions. The objective of the present study was to determine whether serum is the primary source of the IgA which enters uterine secretions in response to estradiol. To examine this, serum IgA levels in rats were surgically elevated by portacaval anastomosis which prevents hepatic clearance of IgA. Under these conditions, IgA levels in serum were 2- to 4-fold higher than those of intact or sham-operated animals. Levels of IgA in uterine secretions of portacaval animals, however, were significantly lower than those measured in controls when animals were ovariectomized and treated with estradiol. IgA in vaginal secretions of portacaval animals was greater than that in sham-operated or intact rats. To determine whether IgA had leaked from the uterus into vaginal secretions, a second group of animals had their uteri ligated at the utero-cervical junction prior to hormone treatment. Following estradiol stimulation, uterine IgA levels in portacaval animals were the same as those measured in intact and sham-operated animals. When free SC was measured in uterine secretions of ligated rats, levels were the same in all three groups. These studies indicate that elevated levels of serum IgA did not lead to a rise in uterine IgA. Further, since SC, which is thought to be a receptor for transporting IgA into mucosal secretions, remained unchanged, it appears unlikely that IgA movement into the uterine lumen was transport limited. These studies suggest that the presence of IgA in uterine and vaginal secretions is not due exclusively to serum contributions but may involve local synthesis of IgA.     

Analysis of paraprotein transport into the saliva by using anti-idiotype antibodies

To determine the extent of clonal involvement of the secretory immune system and the origin of salivary immunoglobulins (Ig) in monoclonal gammopathy patients, saliva and serum samples were collected from five affected individuals (two IgA myelomas, one IgG myeloma, one IgG benign monoclonal gammopathy, and one IgM lymphoma) and were assayed for the presence of monoclonal Ig. Purified polyclonal or monoclonal anti-idiotype (Id) antibodies were prepared against each of the isolated serum paraproteins. In all five individuals, the patient saliva samples inhibited the binding of 125I-labeled homologous Ig to the corresponding anti-Id antibodies, but normal saliva did not. The concentration of Id in patients' saliva varied from 1 to 400 micrograms/ml; i.e., 0.004 to 1.0% of the corresponding serum values. Saliva of a lymphoma patient whose IgM kappa protein exhibited rheumatoid factor (RF) activity also contained RF. The salivary Id-bearing molecules were found to have the same Ig isotype as the serum paraproteins. The myeloma IgA represented a minor component (0.4 and 3.9%) of the total salivary IgA. The salivary IgA myeloma proteins were associated at least in part with secretory component, but the salivary IgG paraproteins were not. In an IgA myeloma patient, a minority (17%) of the IgA+ plasma cells found in the lacrymal gland biopsy specimen were Id+, whereas the great majority (98%) of bone marrow IgA plasma cells were Id+. The results suggest active transport rather than passive transudation of myeloma IgA into the patients' saliva, and the integrity of the secretory immune system was not compromised by the neoplastic process.     

Estradiol and progesterone regulation of immunoglobulin A and G and secretory component in cervicovaginal secretions of the rat

The present study examined the influence of hormones on the levels of immunoglobulins A (IgA) and G (IgG) and secretory component (SC) in cervicovaginal secretions of ovariectomized rats. Administration of estradiol to ovariectomized rats resulted in a significant decline in cervicovaginal content of IgA, IgG and SC. This response was dose dependent and was not prevented by administration of dexamethasone, a potent synthetic glucocorticoid, with estradiol. Treatment of ovariectomized rats with progesterone also lowered the levels of IgA and SC in cervicovaginal secretions. In contrast, dexamethasone had no apparent vaginal effect. The action of estradiol on cervicovaginal IgA, IgG and SC appears to be independent of uterine influence. This conclusion is based upon our observation that estrogen treatment of rats with ligations at their uterocervical junction still have decreased cervicovaginal IgA and SC levels. In parallel with this inhibitory effect, estradiol administration stimulated the accumulation of IgA and SC in uterine secretions. These findings indicate that the sex hormones play a role in regulating IgA, IgG and SC content in cervicovaginal secretions. In addition, it suggests that hormonal balance in females may influence the immune response of the reproductive tract to infectious disease.     

Peculiar secretory IgA system identified in chickens. II. Identification and distribution of free secretory component and immunoglobulins of IgA, IgM, and IgG in chicken external secretions.

A homologue of a free secretory component (SC) was identified in chicken intestinal secretion by criteria based on its antigenic relationship with intestinal secretory IgA (SIgA), molecular size, sugar content, and electrophoretic mobility, as well as its elution characteristic from ion-exchange chromatography. SC was obtained in a form free from IgA from the intestinal secretion by salting out and DEAE chromatography, followed by density ultracentrifuguation or Sephadex G-200 gel-filtration. However, the free SC revealed some antigenic deficiency when compared to bound SC of intestinal SIgA and showed a failure of binding to serum-type-polymeric IgA of biliary IgA in vitro. Several kinds of chicken external secretions were examined for detection of SC and immunoglobulin classes of IgG, IgA, and IgM. In spite of the wide distribution of immunoglobulins in the external secretions, SC antigen could be detected only in intestinal secretion. Most IgA in the secretions had a molecular structure of a tetramer of serum-type IgA, lacking in SC and having 17S to 18.5S and 600,000 to 700,000 daltons. On the other hand, IgA in the intestinal secretion showed close similarity to the mammalian SIgA, associated with SC and having 11.2S and 350,000 daltons. Presence of antibody activity in the intestinal IgA to avian reovirus was confirmed by plaque reduction tests.     

In vivo response of secretory component in the rat uterus to antigen, IFN-gamma, and estradiol

Intrauterine immunization of ovariectomized rats with SRBC is known to elicit pronounced IgA and IgG antibody responses in uterine secretions of immunized uteri. To determine whether secretory component (SC), the receptor for transporting polymeric IgA from tissues to mucosal surfaces, was also influenced by Ag, ovariectomized rats were immunized and boosted by placing SRBC into the lumena of individual uterine horns. In response to Ag, the levels of polymeric IgA, as well as free SC and SC bound to polymeric IgA, increased in uterine secretions. When ovariectomized animals were treated with estradiol, a fivefold increase in SC levels was observed in the immunized horns, indicating that a hormone response is superimposed on the Ag-induced stimulation of uterine SC. To determine whether IFN-gamma influences the presence of SC in uterine secretions, IFN-gamma was placed in the uterine lumena of ovariectomized nonimmunized rats. When uterine secretions were analyzed, significantly higher levels of SC were found in IFN-gamma-exposed uteri than were present in saline treated control animals. In contrast, intrauterine instillation of IFN-gamma had no effect on the levels of IgA in uterine secretions. This response was specific for IFN-gamma in that IFN-alpha/beta had no effect on uterine SC or IgA levels. These results indicate that intrauterine instillation of Ag, in addition to evoking pronounced antibody responses, stimulates the production of SC, which may be responsible for the transport of polymeric IgA from tissue to uterine secretions. Furthermore, they indicate that IFN-gamma placed in the uterine lumen stimulates SC production and suggest that the uterine SC response to Ag may be mediated by the action of IFN-gamma on uterine epithelial cells.     

Glucocorticoid regulation of the humoral immune system. I. In vivo effects of dexamethasone on IgA and IgG in serum and at mucosal surfaces

The present studies were undertaken to determine whether glucocorticoids influence the levels of Ig in serum, saliva, and vaginal secretions. When measured by RIA, IgA levels in serum were elevated when increasing doses of dexamethasone, a potent synthetic glucocorticoid, were administered to intact- and adrenalectomized-ovariectomized rats. In contrast, IgA levels decreased in saliva and vaginal secretions over the same dose range. Time course studies indicated that the decline in salivary IgA, observed at 24 h after a single injection of dexamethasone, preceded a rise in serum IgA detected at 24 h after the second hormone treatment. Both responses were maximal at day 2 and did not change with further hormone exposure. After immunization and boosting with SRBC at two mucosal sites (intestinal Peyer's patch and uterine lumen), dexamethasone increased anti-SRBC IgA antibody levels in serum and reduced their presence in vaginal secretions. In contrast, anti-SRBC IgG-antibody levels in serum and vaginal secretions were reduced with hormone treatment. In the absence of hormone treatment, pooled sera from nonimmunized animals, when analyzed by HPLC, contained polymeric and dimeric IgA that was present in roughly equal proportion. In response to dexamethasone, polymeric IgA increased to a greater extent than did monomeric IgA. In summary, these studies demonstrate that dexamethasone alters the levels of IgA as well as specifically directed IgA and IgG antibodies in secretions and serum. Further, it suggests that glucocorticoid controlled IgA increases in serum and decreases in vaginal and salivary secretions may be due, in part, to a redistribution of polymeric IgA from mucosal surfaces to serum.     

Purification of multiple erythroid cell proteins that bind the promoter of the alpha-globin gene.

Three erythroid cell factors that bind the murine alpha-globin promoter were enriched more than 1,000-fold by conventional and DNA sequence affinity chromatography. Visualization of enriched polypeptides revealed simple patterns suggesting that each binding activity was purified. Two of the purified proteins, alpha-CP1 and alpha-CP2, have been shown previously to interact with distinct binding sites that overlap in the alpha-globin CCAAT box. Affinity purification of alpha-CP1 revealed seven polypeptides with Mrs raging from 27,000 to 38,000. In contrast, purified alpha-CP2 was made up of a polypeptide doublet with Mrs of 64,000 and 66,000. The third purified binding activity, alpha-IRP, interacted with sequences that formed an inverted repeat (IR) between the alpha-globin CCAAT and TATAA boxes. Affinity-purified alpha-IRP was made up of a single polypeptide with an Mr of 85,000. We confirmed that the purified polypeptides corresponded to alpha-CP1-, alpha-CP2-, and alpha-IRP-binding activities by UV cross-linking experiments (alpha-CP2 and alpha-IRP) or by renaturation of binding activity after elution of polypeptides from sodium dodecyl sulfate-polyacrylamide gels (alpha-CP1 and alpha-CP2). The apparent complexity of the polypeptides accounting for alpha-CP1 binding activity prompted a further physical characterization of this factor. Sedimentation of affinity-purified alpha-CP1 in glycerol gradients containing 100 mM KCl showed that all seven polypeptides migrated as a complex that cosedimented with alpha-CP1-binding activity. In contrast, when sedimented in glycerol gradients containing 500 mM KCl, alpha-CP1 dissociated into at least two components. Under these conditions, alpha-CP1-binding activity was reduced or lost. Activity was reconstituted, however, by combining fractions that were enriched in the two components. These results were confirmed by experiments in which we showed that alpha-CP1-binding activity can be recovered only by combining distinct sets of polypeptides that were isolated and renatured from sodium dodecyl sulfate-polyacrylamide gels. Our results suggest that the seven polypeptides visualized after affinity purification of alpha-CP1 interact to form a heterotypic complex (or set of complexes) required for alpha-CP1-binding activity.     

Serum and secretory immunoglobulins in allergic diseases

A total of 158 patients with pollinosis, bronchial asthma, urticaria and Quincke's edema were examined. The immunoglobulin and C3 levels in sera and the immunoglobulin and albumin levels in saliva were determined by the method of single radial immunodiffusion with the corresponding monospecific antisera. In all the groups of patients subjected to examination the presence of polyclonal hypergammaglobulinemia was detected, which was manifested by a rise in the levels of IgG, IgA and especially IgM; the level of IgD was low. A decrease in the level of C3 was detected in pollinosis patients in the absence of the exacerbation of the disease. No circulating immune complexes were detected. An essential increase in the level of IgG in saliva was revealed, which was due to the local synthesis of this immunoglobulin. In winter the level of salivary IgA in pollinosis patients was found to be essentially below normal, but at the period of exacerbation it increased twofold, probably in response to local stimulation with antigen-allergen. Patients with bronchial asthma and pollinosis were found to have a high level of free secretory component (SC); in pollinosis the level of free SC sharply increased during the stage of exacerbation, which was due to the increase of its synthesis and secretion by the epithelial cells of the mucous membranes. The importance of these data for the pathogenesis of allergic diseases are discussed.     

猕猴和小鼠分泌片的分离纯化及某些生化特性

为了深入了解分泌片和ＩｇＡ在粘膜免疫系统中的作用,自猕猴和小鼠胆汁中提取和纯化分泌片,ＳＤＳ－ＰＡＧＥ结果表明猕猴和小鼠游离分泌片的分子量均约为６０ｋＤａ,但在非解聚型聚丙烯酰胺梯度凝胶电泳时分子量分别为７４ｋＤａ和６２ｋＤａ。采用ＬＫＢ－８１００等电聚焦柱测定其ＰＩ范围,猕猴分泌片为４．３－５．９,小鼠分泌为３．９－５．４。免疫双扩散证明,猕猴和小鼠胆汁中的分泌片均能与兔抗人分泌片免疫血清发生交     

Analysis of the humoral responses of Toxoplasma gondii-infected cats using immunofluorescent assays with tachyzoite, bradyzoite, and gametogenic stages

We investigated levels of Toxoplasma gondii specific antibodies present in sera, intestinal secretions, and fecal extracts obtained from cats following primary and challenge infections. Antibodies specific to T. gondii tachyzoites, bradyzoites, sporozoites, and enteroepithelial stages were detected by indirect immunofluorescence assay. Enteroepithelial stage-specific antibodies were detected in serum as early as 2 wk after infection, whereas antibodies from intestinal secretions did not appear until 3 wk following infection. The T. gondii-specific IgG and IgA antibodies were present in serum, but only specific IgA antibodies were detected in the intestinal secretions. Serum IgG bound to tachyzoites, bradyzoites, sporozoites, and enteroepithelial stages of T. gondii, whereas serum IgA bound strongly to enteroepithelial stages but only weakly to tachyzoites and bradyzoites. IgA from intestinal secretions bound to antigens on all enteroepithelial stages and the distal tips of sporozoites and bradyzoites but did not bind to tachyzoites. IgA present in fecal extracts also bound to enteroepithelial stages of T. gondii. Toxoplasma gondii infection in cats induces the production of antibodies that bind with all forms of the parasite, including the enteroepithelial stages. Comparison of the staining patterns of T. gondii stages for serum and intestinal secretion IgA indicated differences. Thus, the intestinal antibody immune response may be uniquely focused on the intestinal stages relative to the circulating antibodies, resulting in a compartmentalization of the humoral response.     

Secretory immunoglobulin A: from mucosal protection to vaccine development

Immune responses taking place in mucosal tissues are typified by secretory immunoglobulin A (S-IgA) molecules, which are assembled from proteins expressed in two cell lineages. The heavy and light chains as well as the J chain are produced in plasma cells, whereas the secretory component (SC) is associated to the immunoglobulin complex during transcytosis across the epithelial layer. S-IgA antibodies represent the predominant immunoglobulin class in external secretions, and the best defined entity providing specific immune protection for mucosal surfaces by blocking attachment of bacteria and viruses. S-IgA constitutes greater than 80% of all antibodies produced in mucosa-associated lymphoid tissues in humans. The existence of a common mucosal immune system permits immunization on one mucosal surface to induce secretion of antigen-specific S-IgA at distant sites. In addition, S-IgA antibodies not only function in external secretions, but also exert their antimicrobial properties within the epithelial cell during transport across the epithelium. Passive mucosal delivery of monoclonal IgA molecules neutralizes pathogens responsible for gastrointestinal and respiratory infections. Mucosal and systemic immunity can be achieved by orally administered recombinant S-IgA molecules carrying a protective bacterial epitope within the SC polypeptide primary sequence.     

Identification of protein components in human acquired enamel pellicle and whole saliva using novel proteomics approaches

Precursor proteins of the acquired enamel pellicle derive from glandular and non-glandular secretions, which are components of whole saliva. The purpose of this investigation was to gain further insights into the characteristics of proteins in whole saliva and in vivo formed pellicle components. To maximize separation and resolution using only micro-amounts of protein, a two-dimensional gel electrophoresis system was employed. Protein samples from parotid secretion, submandibular/sublingual secretion, whole saliva, and pellicle were subjected to isoelectric focusing followed by SDS-PAGE. Selected protein spots were excised, subjected to "in-gel" trypsin digestion, and examined by mass spectrometry (MS). The data generated, including peptide maps and tandem MS spectra, were analyzed using protein data base searches. Components identified in whole saliva include cystatins (SA-III, SA, and SN), statherin, albumin, amylase, and calgranulin A. Components identified in pellicle included histatins, lysozyme, statherin, cytokeratins, and calgranulin B. The results showed that whole saliva and pellicle have more complex protein patterns than those of glandular secretions. There are some similarities and also distinct differences between the patterns of proteins present in whole saliva and pellicle. MS approaches allowed identification of not only well characterized salivary proteins but also novel proteins not previously identified in pellicle.     

Progesterone regulation of secretory component (SC): uterine SC response in organ culture following in vivo hormone treatment

Sex steroid hormones are known to have profound effects on mucosal immunity. In the present study we evaluated the effects of progesterone on the uterine immune system by determining the changes in the levels of secretory component (SC) released from uterine tissues in culture following in vivo administration of progesterone to estradiol-stimulated ovariectomized rats. SC is a transport protein which moves IgA into external secretions such as intestinal and uterine secretions. SC release was determined by radioimmunoassay of the culture medium collected 24 h after introduction of uterine tissues into medium with or without cycloheximide. The net production of SC was reduced following progesterone administration. Reduction in SC levels followed a dose dependency and occurred irrespective of whether the progesterone was given before or during treatment with estradiol. These results support the hypothesis that progesterone plays a direct role in suppression of uterine SC production and release.     

Nasal Immunization of Mice with Human Papillomavirus Type 16 Virus-Like Particles Elicits Neutralizing Antibodies in Mucosal Secretions

To specifically induce a mucosal antibody response to purified human papillomavirus type 16 (HPV16) virus-like particles (VLP), we immunized female BALB/c mice orally, intranasally, and/or parenterally and evaluated cholera toxin (CT) as a mucosal adjuvant. Anti-HPV16 VLP immunoglobulin G (IgG) and IgA titers in serum, saliva, and genital secretions were measured by enzyme-linked immunosorbent assay (ELISA). Systemic immunizations alone induced HPV16 VLP-specific IgG in serum and, to a lesser extent, in genital secretions but no secretory IgA. Oral immunization, even in the presence of CT, was inefficient. However, three nasal immunizations with 5 μg of VLP given at weekly intervals to anesthetized mice induced high (>10⁴) and long-lasting (>15 weeks) titers of anti-HPV16 VLP antibodies in all samples, including IgA and IgG in saliva and genital secretions. CT enhanced the VLP-specific antibody response 10-fold in serum and to a lesser extent in saliva and genital secretions. Nasal immunization of conscious mice compared to anesthetized mice was inefficient and correlated with the absence of uptake of a marker into the lung. However, a 1-μg VLP systemic priming followed by two 5-μg VLP intranasal boosts in conscious mice induced both HPV16 VLP-specific IgG and IgA in secretions, although the titers were lower than in anesthetized mice given three intranasal immunizations. Antibodies in serum, saliva, and genital secretions of immunized mice were strongly neutralizing in vitro (50% neutralization with ELISA titers of 65 to 125). The mucosal and systemic/mucosal HPV16 VLP immunization protocols that induced significant titers of neutralizing IgG and secretory IgA in mucosal secretions in mice may be relevant to genital HPV VLP-based human vaccine trials.     

A novel idiotopic determinant on phosphorylcholine-binding immunoglobulins restricted to isotype and allotype

A shared idiotopic (Id) determinant, designated B24-50, was detected on phosphorylcholine (PC)-binding myeloma proteins by using a monoclonal antibody. Analysis of immune sera from inbred and congenic strains of mice revealed the presence of this Id determinant on a very small proportion of the PC-binding immunoglobulins (Ig). Hybridoma and myeloma proteins of various classes were analyzed for B24-50 expression, and a clear association of B24-50 with IgA was demonstrated. The Id was found on two distinct idiotypic families, (TEPC15 and McPC603), which share a similar heavy chain but have different light chains; however, isolated heavy chains did not express B24-50. The Id did not require the absolute association of the TEPC15 light chain V kappa 22 with the TEPC15 heavy chain but appeared dependent upon the interaction of the light chain with the TEPC15 heavy chain via quaternary interactions and/or shared amino acid residues of V kappa 8 (M603) and V kappa 22. Furthermore, B24-50 was not found on IgA of strains with the Ighb allotype. Thus B24-50 is a novel isotype-restricted determinant found on two Id families and is influenced by the Igh allotype.     

Proteomic analysis of secretion from human transplanted submandibular gland replacing lacrimal gland with severe keratoconjunctivitis sicca

Purpose: Proteomic analysis of secretions from transplanted or non-transplanted submandibular glands in patients with severe keratoconjunctivitis sicca and tears from normal eyes. Experimental design: Secretions from submandibular glands transplanted to replace lacrimal glands and non-transplanted submandibular glands were collected at 1year from 5 patients with severe keratoconjunctivitis sicca undergoing transplantation, and tears were collected from 3 normal subjects. 2-D electrophoresis (2-DE), then mass spectrometry was used to identify proteins. Western blot analysis was used to confirm protein expression. Results: We identified 34 and 11 distinct proteins in the saliva from transplanted submandibular glands and tears, respectively. The saliva from transplanted submandibular glands contained almost all the proteins abundant in tear fluid. The functions of identified proteins in the saliva from transplanted submandibular gland were mainly immune response and anti-bacterial. In total, 7 proteins showed differential expression between the saliva of transplanted and non-transplanted submandibular glands. The upregulation of short palate, lung and nasal epithelium carcinoma-associated protein 2 and carbonic anhydrase VI was confirmed by Western blot analysis. Conclusions: Identified proteins in saliva from transplanted submandibular glands may protect ocular structures. These findings can help in understanding the functional status of transplanted submandibular glands.     

Mucosal and systemic antibody responses in humans infected with simian foamy virus

Simian foamy virus (SFV) infection and the subsequent immune response are not well characterized. Blood plasma, saliva, and urine were obtained from four humans and nine chimpanzees persistently infected with chimpanzee-type SFV for an unknown length of time. SFV-specific immunoglobulin G (IgG) antibodies, but not IgA antibodies, against the Gag and Bet proteins were detected, by Western blotting, in all sample types from infected humans and chimpanzees. Overall, chimpanzee samples had higher anti-SFV IgG titers than humans. These results provide a first comparative evaluation of SFV-specific host mucosal humoral immunity in infected humans and chimpanzees that is characterized by a predominant IgG response and a virtually absent IgA response.